Recovery system and ink jet recording apparatus provided with said recovery system

ABSTRACT

A recovery system comprises a cap means for covering the discharging ports of a recording head to perform recording by discharging ink, and a wiper assembly for wiping the discharging port face of the recording head, the wiper assembly being a large-sized wiping member and a small-sized wiping member, wherein the small-sized wiping member is first in contact with the discharging port face of the recording head. A guide member guides the recording head and the cap at the time of mating and a holder holds the recording head and cap, which holder holds the recording head and said cap in such a manner that they can relatively be displaced in the direction crossing the contacting direction thereof. A cap unit with the cap and wiper assembly can be rotated within a rotational area of the recording head. Wiping by the wiper assembly is performed in such a manner that following the rotation of the recording head, the small-sized wiping member is first in contact therewith and subsequently, the large-sized wiping member is in contact therewith.

This application is a continuation of application Ser. No. 08/347,176filed Nov. 22, 1994, now abandoned which is a continuation ofapplication Ser. No. 08/138,376 filed Oct. 19, 1993, now abandoned,which is a continuation of application Ser. No. 07/655,161 filed Feb.13, 1991, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recovery system applicable to an inkjet recording apparatus, etc., and to an ink jet recording apparatusprovided with said recovery system.

2. Related Background Art

Conventionally, a recording apparatus, such as a printer, a copier, afacsimile, etc., is of such a construction that an image formed with dotpatterns is recorded on a recording sheet, such as paper, thin plasticplate, etc., by driving the energy generating member of a recording headin accordance with image information being received.

An ink jet recording apparatus used as such a recording apparatus has anadvantage that the noise at the time of recording is extremely small andthat a high-density multi-discharging port can be mounted with ease,thereby making it possible to perform high-speed recording. Also withink jet recording, it is easy to perform color reproduction of a colorimage, so this type of recording apparatus is increasingly becoming ofinterest to those in the art recently.

Particularly, with a method of discharging ink droplets to eject withthe utilization of heat energy, in which flow passages can be formed bythin film technique, it is possible to obtain a high density most easilyamong all recording methods. Such method, therefore, is just suited tohigh-speed recording.

As an example of recording head employed for an ink jet recordingapparatus such as this, there is a recording head having a plurality ofdischarging ports formed across the entire recording width of recordingsheet, i.e., a recording head of the socalled full line type.

Each of the aforesaid plural discharging ports is connected to a commonliquid chamber built inside of the recording head. To this common liquidchamber, a plurality of ink supply tubes (two, for example) areconnected from an ink tank storing ink to be supplied to the recordinghead in such a fashion that at the time of recording ink is suppliedfrom both of the supply tubes while at the time of a recovery operationfor the recording head, one-way flow of ink is generated in thedirection sequentially towards the ink tank, one of the supply tubes,recording head, the other supply tube, and back to ink tank.

Nevertheless, due to ink evaporation and drying, stains caused by inkleakage and adhesion of dust, generation of air bubbles in the inksupply passages, or the like, the ink jet recording head may besubjected to defective ink discharging, and there is a possibility thatthe quality of recorded image is lowered. In order to prevent thisdefective discharging, it is necessary to clean off the dischargingports of the head with a blade or to perform discharging of ink from allof the ports just for cleaning purposes during recording or at the timeof off recording, or it is required to perform the recovery operationfor the recording head by performing the aforesaid one-way flow of inkamong others. There is also a need for tightly closing the dischargingports when the head is not in use. To this end, capping means should beprovided, and its structure should be arranged so as to enable therecording head to move from the recording position for capping.

Conventionally, as means to construct the recovery means, capping meansis used for tightly closing the nozzles of an ink jet head.

Here, the cap of a capping means is made of plastic material such asrubber, etc., and when an ink jet printer is not performing a recordingoperation, such cap is pressed against the ink jet head to tightly closethe nozzle section to keep it from the atmosphere for preventing drying.In this instance, the aforesaid tight closure is effectuated by causingthe faces of the cap and ink jet head to be in contact with each other.

For the conventional recording head of full line type, however, there isa problem that it is difficult to press discharging ports with a closedspace provided by a cap while a member for pressing the dischargingports should be maintained in parallel with the cap stably andaccurately.

Also, as another means to construct the recovery means, there istraditionally known wiping means to clean off ink adhered to the face ofthe orifice of an ink jet head. This wiping means is of such a structurethat ink is cleaned off by moving the face of the orifice of the ink jethead in a direction at right angles to the wiper.

However, since many discharging ports are generally provided on theorifice face, there arises a problem that the recorded image isadversely affected. Further, if the hardness of the wiper is enhanced orthe thickness thereof is increased, the contacting pressure between thewiper and the orifice face becomes greater. Then, the wiper itself isworn by friction, and ink cannot be cleaned off where the portion ofwiper has been worn out. Hence, a problem is encountered that adefective image is also produced.

SUMMARY OF THE INVENTION

A principle object of the present invention is to provide a recoverysystem to solve the aforesaid problems by simply adding a new structureto capping means and wiping means, and an ink jet recording apparatusprovided with said system.

Another object of the present invention is to provide a recovery systemsuitably used for a recording head of full line type, and an ink jetrecording apparatus provided with said recovery system.

Still another object of the present invention is to provide a recoverysystem capable of pressing discharging ports of recording head of fullline type with a member for pressing discharging ports while maintaininga closed space provided by a cap, and an ink jet recording apparatusprovided with said recovery system.

Still another object of the present invention is to provide a recoverysystem capable of effectively removing ink, dust, etc. adhered to theface of discharging ports of recording head of full line type, and anink jet recording apparatus provided with said recovery system.

Yet another object of the present invention is to provide a recoverysystem capable of suitably removing ink, dust, etc. adhered to the faceof discharging ports by suitably maintaining the contacting pressure ofwiper against the face of discharging ports, and an ink jet recordingapparatus provided with said recovery system.

A further object of the present invention is to provide a recoverysystem comprising:

capping means for covering the discharging ports of recording head fordischarging ink onto recording medium for recording;

wiping means having a large-sized wiping member and a small-sized wipingmember, said small-sized wiping member first wiping the face ofdischarging ports of the aforesaid recording head being in contact withthe face of discharging ports of the aforesaid recording head;

guide means for guiding the aforesaid recording head and the aforesaidcapping means at the time of mating;

holding means for holding the aforesaid recording head and the aforesaidcapping means in such a manner that the positions of these means canrelatively be displaced in the direction crossing the contactingdirection of the aforesaid recording head and the aforesaid cappingmeans; and

a cap unit having the aforesaid capping means and the aforesaid wipingmeans being rotatable within the rotational area of the aforesaidrecording head.

Still a further object of the present invention is to provide an ink jetrecording apparatus comprising:

a recording head for discharging ink onto recording medium forrecording;

capping means for covering the discharging ports of recording head fordischarging ink onto recording medium for recording;

wiping means having a large-sized wiping member and a small-sized wipingmember, said small-sized wiping member first wiping the face ofdischarging ports of the aforesaid recording head being in contact withthe face of discharging ports of the aforesaid recording head;

guide means for guiding the aforesaid recording head and the aforesaidcapping means at the time of mating;

holding means for holding the aforesaid recording head and the aforesaidcapping means in such a manner that the positions of these means canrelatively be displaced in the direction crossing the contactingdirection of the aforesaid recording head and the aforesaid cappingmeans.; and

a cap unit having the aforesaid capping means and the aforesaid wipingmeans being rotatable within the rotational area of the aforesaidrecording head.

Still a further object of the present invention is to provide a methodfor ink jet recording comprising:

a recording head for discharging ink onto recording medium forrecording;

capping means for covering the discharging ports of recording head fordischarging ink onto recording medium for recording; wiping means havinga large-sized wiping member and a small-sized wiping member, saidsmall-sized wiping member first wiping the face of discharging ports ofthe aforesaid recording head being in contact with the face ofdischarging ports of the aforesaid recording head; guide means forguiding the aforesaid recording head and the aforesaid capping means atthe time of mating; holding means for holding the aforesaid recordinghead and the aforesaid capping means in such a manner that the positionsof these means can relatively be displaced in the direction crossing thecontacting direction of the aforesaid recording head and the aforesaidcapping means; and a cap unit having the aforesaid capping means and theaforesaid wiping means being rotatable within the rotational area of theaforesaid recording head. Still a further object of the presentinvention is to provide an ink jet recording apparatus comprising: anink jet recording head for discharging ink to perform recording onrecording medium; capping means for covering the discharging ports ofthe aforesaid ink jet recording head; holding means for holding theaforesaid ink jet recording head and the aforesaid capping means in sucha manner that these means can relatively be displaced in the directioncrossing the contacting direction of the aforesaid ink jet recordinghead and the aforesaid capping means; and

guide means for guiding the aforesaid ink jet recording head and theaforesaid capping means at the time of mating.

Yet a further object of the present invention is to provide an inkjet-recording apparatus comprising:

an ink jet recording head for discharging ink to perform recording onrecording medium;

a large-sized cleaning member for cleaning the orifice face of theaforesaid ink jet recording head;

a small-sized cleaning member being smaller than the aforesaidlarge-sized cleaning member; and

the aforesaid small-sized cleaning member being arranged to be first incontact with the aforesaid recording head at the time of cleaning.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional side view showing a facsimile apparatus towhich an embodiment of the present invention is applied.

FIG. 1B is a top plan view of the apparatus shown in FIG. 1A.

FIG. 2 is a cross-sectional side view showing the state where theapparatus shown in FIG. 1A is opened.

FIG. 3 is a perspective view showing the vicinity of a platen roller.

FIG. 4 is a perspective view showing an exhaust sheet roller.

FIG. 5 is a perspective view showing a recording frame.

FIG. 6 and FIG. 7 are side views showing the vicinity of a recordinghead.

FIG. 8 is a perspective view showing the recording head.

FIG. 9 is a perspective view showing the vicinity of a cap.

FIGS. 10A-10C are views showing the state immediately after the head andthe cap are in contact with each other.

FIGS. 11A and 11B are views showing the state where the head and the capare apart from each other.

FIGS. 12A-12C are views showing the state where the cap is being movedtowards the head.

FIGS. 13A-13C are views showing the state where a projection presses anozzle to be tightly closed while a spring is resiliently deformed.

FIGS. 14A-14C are views showing the state where the cap is being partedfrom the head.

FIGS. 15A-15C are views showing the standby state of the cap.

FIG. 15D is a view showing a guide member according to anotherembodiment of the present invention.

FIG. 15E is a view showing a guide member according to still anotherembodiment of the present invention.

FIG. 16 is a typical view schematically showing a structural example ofthe ink supply passage of an ink jet recording apparatus according tothe present invention.

FIG. 17 is a perspective view showing a structural example of inksupplying means of an ink jet recording apparatus according to thepresent invention.

FIG. 18 is an exploded perspective view showing an structural example ofan ink cartridge installed in an ink jet recording apparatus accordingto the present invention.

FIGS. 19A and 19B are a partially cutaway sectional side view showingthe structural example of the ink cartridge and a partially enlargedview thereof to show the state of mating with the ink supplying means.

FIG. 20 is a partially cutaway sectional front view of the structuralexample of the ink cartridge.

FIG. 21 is a schematic top view showing the structural example of theink cartridge.

FIG. 22 is a flowchart showing an example of sequential recoveryapplicable to an ink jet recording apparatus according to the presentinvention.

FIGS. 23A-23D are schematic side views sequentially showing the recoveryoperation.

FIG. 23E is a typical view showing the contacting amount and contactingangle of the leading end of a blade being in contact with the face of adischarging port.

FIG. 24 is a flowchart showing an example of the sequence from thestandby state to the recording state.

FIG. 25 is a block diagram showing a recording unit according to anembodiment of the present invention.

FIG. 26 is a flowchart showing an operation at the time of recordingaccording to an embodiment of the present invention.

FIG. 27 is a flowchart showing a recovery operation according to anembodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter the present invention will specifically be described inaccordance with embodiments.

FIG. 1A is a central sectional view showing an embodiment of facsimileapparatus characteristically representing the present invention. FIG. 1Bis a top plan view thereof, and FIG. 2 is a cross-sectional view showingthe apparatus in an open state. The facsimile apparatus of the presentembodiment roughly comprises original conveying system A, optical systemB, power source unit C, electric circuit board D, recording sheetconveying system E, decurling system F, ink supply system G, andrecovery system H. Here, the aforesaid original conveying system A andoptical system B constitute an original reading unit for readingoriginal images. Then, as the basic action of a facsimile apparatus,when an original 2 is set for transmitting or copying, originalconveying system A conveys the aforesaid original 2 sequentially by aroller train (rollers R1, R2, R3, and R4) driven by driving means (notshown) in order to read the original image of original 2. Thus, theoriginal line information is transferred by condenser lens Le to lineCCD 100 through the reflective optical path of optical system B (lampL1, mirrors M1 and M2) from a given position for reading the originalline (main scanning line) in the course of its conveyance, and isconverted into electrical signals for the reading of the originalinformation. At the time of receiving or copying, recording sheetconveying system E sequentially conveys recording sheet, which is woundin a roll, by a roller train driven by driving means (not shown) to apassage shown in FIG. 1, and recording is performed in the coursethereof by discharging ink from discharging ports of recording head 38onto a given recording line of the recording sheet. Ink is dischargedfrom the discharging ports of recording head 38 with the utilization ofheat energy. This heat energy is generated by an electric heat converterprovided in recording head 38. In this respect, power source unit Creceived a normal AC to convert it into all the necessary voltagecurrents and supplies them respectively to each of the units of theapparatus. The electric circuits with electric circuit board D at itscenter controls the functional operation of each unit of this apparatusmainly with a microcomputer system provided. It also performs theconnection and disconnection with transmission line as well as the inputand output of image information signals. Ink supply system G suppliesink to the recording head, and recovery system H performs the cleaningand capping of the face of discharging ports, which are needed for themaintenance of the head.

In this respect, as shown in FIG. 1B, rolled recording sheet 1 ispositioned almost in the center of the apparatus, and on the left-handside thereof, original conveying system A, optical system B, and powersource unit C are arranged in the vertical direction, and on theright-hand side thereof, recording head 38, record head recovery systemH, and ink supply system G with ink tank 86 are arranged sequentially inthat order from the above. Since recording head 38, recording headrecovery system H, and ink supply system G are thus arrangedsequentially from the above, the ratio of pressure variation of ink tank86 against the orifice face of recording head 38 is reduced (i.e., thepressure against each of the discharging ports is equalized) even if theapparatus is inclined according to the present embodiment, and anexcellent recording can be performed. This is due to an arrangement suchthat despite the miniaturization of the apparatus, the space between theorifice face of recording head and the ink tank 86 is made greater.

Hereinafter, each structure of recording head and operation will bedescribed following its operational sequence. Rolled recording sheet 1is installed, and is pinched by driving feed roller 7 and free roller(platen roller) 8 which is in contact with said driving roller 7 throughdecurling system F for straightening out the curl formed on thisrecording sheet 1. Feed roller 7 is driven by driving means (not shown)with, for example, a stepping motor as its power source.

Here, FIG. 3 is a perspective view showing parts arranged in thelongitudinal direction in the vicinity of free roller 8 (platen roller).A first platen side plate 13a and a second platen side plate 13b fixedto or integrally formed with recording frame 19 support free roller 8with a play in such a manner that the shaft of the free roller ispenetrated through the opening 13c provided each of the side plates,having a larger diameter than that of the shaft. The E rings 29 and 30are fixed respectively at both ends of the shaft of free roller 8 aslocks and further, on both shaft parts of free roller 8, bearings 10aand 10b, the inner and outer diameters of which are accurately regulatedto provide an equal coaxiality, are fittedly mounted on the shaft offree roller 8 to enable it to be freely rotated. In the meantime, theaforesaid first platen side plate 13a and second platen side plate 13bare slidably arranged each with the respective platen pressure shaft 12aand 12b mounted on the inner side thereof as shown in FIG. 3. Then, bythe functions of springs 11a and 11b, the aforesaid platen pressureshafts 12a and 12b are in contact with bearings 10a and 10b of theaforesaid free roller 8 respectively to exert pressure against each ofthem.

Now, reverting to FIG. 1, recording head 38 is at the recordingposition. At this juncture, free roller 8 is positioned by being incontact in two directions with feed roller 7 by the pressure exerted byfree roller 8 as well as with recording head 38 by contacting theaforesaid bearings 10a and 10b. In other words, the direction, in whichthe pressures of platen pressure shafts 12a and 12b of free roller 8 areexerted, is set towards the direction that free roller 8 is in contactwith free roller 7 and that bearings 10a and 10b are in contact withrecording head 38. At the same time, recording guide 14 made of thinplastic plate guides the aforesaid recording head 38, so that therecording head is rotated to the recording position with head shaft 36as its rotational center.

Thus, the sheet path is matched with the recording line position, andrecording head 38 discharges ink from its discharging ports onto theaforesaid recording line position for recording at the time ofrecording.

Next, recording sheet 1 is pinched by first exhaust sheet roller 21 andthe roller train 17a-17g and roller train 18a-18g which are in contactwith the aforesaid first exhaust sheet roller 21 to be conveyed whilebeing guided by first curvature guide 15 and first exhaust sheet guide20.

In this respect, the aforesaid first exhaust sheet roller 21 is drivenby the driving system of the same power source as feed roller 7, and isso arranged that the peripheral speed of the aforesaid first exhaustsheet roller 21 is slightly faster than that of the aforesaid feedroller 7.

Here, FIG. 4 is a perspective view showing the parts arranged in thelongitudinal direction in the vicinity of first exhaust sheet roller 21.Rollers 17a-17g and rollers 18a-18g are arranged alternatively withfirst curvature guides 15a-15f. Each of them is rotatably supported byshaft 31 and shaft 32 and both ends of the shafts are locked by E rings,etc. Also, at both ends, shaft 32 is regulated by receiving side 9a ofthe first exhaust sheet rollers, which is fixed to or integrally formedwith recording frame 19 and receiving side 19b of the second exhaustsheet rollers, and also in the horizontal direction, the shaft isregulated at both ends thereof by the vertically elongated through holeshaving the diameter fitted to that of shaft 32, through which the shaftis penetrated. Both ends of the shaft are also locked by E rings (notshown), etc. In this respect, compression is generated by springs16a-16f represented only by a reference numeral 16a in FIG. 4 forrecording chassis 19 and first curvature guides 15a-15f (refer toFIG. 1) to cause rollers 17a-17g and rollers 18a-18g to be in contactwith exhaust sheet roller 21 by pressure. As a result, when recordingsheet 1 is pinched thereby, the power to convey the recording sheet isgenerated. Then, recording sheet 1 is guided to upper exhaust sheetguide 23 and trailing exhaust sheet guide 24 through the space betweenboth edges 22a and 22b which cut the recording sheet into each of thereceiving one pages and is further guided and conveyed by second exhaustsheet roller 25 and the rollers 27a-27g and rollers 28a-28g which are incontact therewith. In this respect, second exhaust sheet roller 25 isalso driven by the driving system in such a manner that the peripheralspeed thereof is set at a speed slightly faster than that of theaforesaid first roller 21. Here, too, as in the vicinity of theaforesaid first exhaust sheet roller 21, rollers 27a-27g and rollers28a-28g are arranged alternately with second curvature guides 26a-26fand are rotatably supported respectively by shaft 33 and shaft 34. Then,both ends of shaft 34 are locked with E rings, etc. Shaft 33 isregulated at both ends thereof by exhaust sheet roller receiving sides19c and 19d fixed to or integrally formed with recording frame 19,having vertically elongated holes fitted respectively to the diameter ofshaft 33, through which both ends of the shaft are penetratedhorizontally. The ends thereof are also locked by E rings, etc. Withsprings 35a-35f, compression is generated between recording frame 19 andsecond curvature guides 26a-26f (refer to FIG. 1) to cause rollers27a-27g and rollers 28a-28g to be in contact with second exhaust sheetroller 25 by pressure, so that when recording sheet 1 is pinchedthereby, the conveying power is generated. In this way, the recordingsheet is exhausted after recording has been completed, and is furtherconveyed by exhaust sheet roller 39 in the form of being cut into theunit of one page while the leading and thereof is being held smoothly bystacker 40. As a result, an operator can take out the recording sheetthus stacked on stacker 40.

As the above describes, the recording sheet conveying system isstructured to carry out its operation. Here, FIG. 1 shows the state ofthe system at the time of recording, and at the time of replacing therecording sheets or troubleshooting in conveying recording sheet,recording frame 19 can be opened or closed with hinge 19e of recordingframe 19 as its pivoting point. In other words, as shown in FIG. 2, therecording frame can be opened just along the recording sheet conveyingpath as its boundary, and the arrangement is designed to place each ofthe components belonging to recording frame 19 above this boundary andeach of those belonging to main body frame 63 below the boundary. Thisrecording frame 19 and the assembly of its components thereon are shownin FIG. 5.

As set forth above, in the present embodiment, recording head 38,recording head recovery system H, and ink supply system G aresequentially arranged from the above in that order. Thus, recordingsheet 1 is guided in the horizontal direction above recording head 38after the recording has been completed by recording head 38, and isfurther conveyed downwards thereafter to exhaust sheet stacker 40 forstacking. Here, the path through which the aforesaid recording sheet isbeing guided in the aforesaid horizontal direction forms the aforesaidboundary along which the main body is opened. Therefore, according tothe present embodiment, it is easy to remove a clogged sheet if anyclogging should occur, and further, it is possible to perform cappingwithout damaging the head face when a sheet clogging takes place. Inaddition, should an ink leakage occur while capping, the recording sheetis not stained.

Next, the positioning of free roller 8 (platen roller) will bedescribed.

First, FIG. 6 illustrates the state of parts in the vicinity of freeroller 8 when the main body of the apparatus is in standby. Recordingguide 14 is not allowed to be in contact with free roller 8 unless thereis external force to be exerted thereon. Accordingly, the contactingangle of recording sheet 1 to the periphery of free roller 8 is less inthe standby state than in the printing state. At this juncture, theposition of free roller 8 is established by the fact that the peripheryof free roller 8 is pressed by platen pressing shafts 12a and 12b to bein contact with feed roller 7, and that the shaft of free roller 8 is incontact with through hole 13c, which is larger than the periphery of theaforesaid shaft by 0.1 mm-several mm, provided on each of platen sideplates 13a and 13b. Here, the aforesaid feed roller 7 and free roller 8are made of plastic material such as rubber, etc. rolled around a rigidshaft made of iron, etc.

Next, FIG. 7 illustrates recording head 38 being rotated clockwise withthe head shaft as its rotating center in order to shift itself from thestandby state to recording state. When head 38 is first rotated asdescribed earlier by the driving power generated by motor KM, aplurality of projections provided on the recording face of head 38 arein contact with the top of recording guide 14 to cause recording guide14 to begin resiliently deforming it. Here, projection 38c provided onthe recording face of head 38 is made to be increasingly higher towardsthe corner. Thus, recording guide 14 is deformed apart from recordinghead 38 by the height (6 in FIG. 7) of the aforesaid projection.

The reason why the aforesaid projection 38c is arranged to beincreasingly higher towards the corner is to make it easier to removeink when the recording face of the head is wiped as described later.

Recording head 38 is further rotated clockwise, and when recording head38 is moved to be in the recording state as shown in FIG. 1, both endsof the recording face of recording head 38 are in contact with bearings10a and 10b. Hence, the space between the recording face of recordinghead 38 and platen roller (free roller) 8 is established. In the presentembodiment, the periphery of bearings 10a and 10b is made larger thanthat of free roller 8, and the volume thereof is set to be less than theheight δ of the aforesaid projection of recording head 38 by a l/severalmm thereof. Thus, guide 14 is reliably in contact with the periphery ofplaten roller 8 to convey the recording sheet. Here, at the time ofrecording, the aforesaid feed roller 7 is rotated clockwise, and platenroller 8 is rotated counterclockwise by the external force generated bythe feed roller, at the same time, being moved in the direction towardsthe recording head 38. Hence, with the structure described earlier, theaforesaid platen roller 8 is brought to contact with guide 14 throughrecording sheet. Therefore, the aforesaid springs 11a and 11b are notnecessarily needed here, and platen roller 8 can also be in contact withthe guide only by its own weight.

Next, using the perspective view shown in FIG. 8, the structures ofperipheral parts of recording head 38 will be described. Recording head38 mainly comprises head main body 38f including a heat generatingsection, electrical part section, and glass chamber section forcontaining liquid ink, front filter 38d and rear filter 38e arrangedrespectively at the outside of the head main body, and head front plate38c. Also, front head ink connection 38d₁ and rear head ink connection38e₁ are respectively provided for front filter 38d and rear filter 38e.These are tightly closed and connected respectively by front ink supply71 and ink supply tube threading with sealing members (not shown)provided therebetween. A reference numeral 38a designates an imaginarytwo-dot chain line in FIG. 8 to represent the straight line formed byconnecting the center lines of the nozzles aligned. A plurality ofnozzles are aligned in order to form image on a recording materialacross the entire width thereof in the direction of main scanning.Hereinafter, these are referred to as nozzles 38a. In practice, however,holes of several ten microns in diameter are provided, and the aforesaidholes are connected to ink supply tubes 71 and 72. Here, the oppositeends of ink supply tubes 71 and 72 are respectively connected to frontsupply tube joint 84 and rear supply tube joint 85. Now, in FIG. 8, areference numeral 38b designates the face where nozzle 38 is open, whichis called orifice face. In this respect, front head plate 38g is formedby metal or molding material, and the space between orifice face 38b andfront head plate 38g is filled with silicone rubber, etc. to close themcompletely. Filters 38d and 38e are arranged to prevent dusts in the inkfrom flowing into the nozzle section. Reference numerals 37a and 38bdesignate front and rear head arms made of engineering plastic, sinteredmetal, diecast metal, or the like, which has rigidity and resistivityagainst thermal deformation at high temperatures, and each of them isfixedly mounted on BJ head 38 by means of screws, etc.

Front head arm 37a and rear head arm 37b are fixedly mounted on headshaft 36 by means of screws, etc., and with the structure as describedearlier, head shaft 36 and BJ head 38 are fixed arranged. Head shaft 36is rotatably supported by main body frame 56 through bearings (notshown). Head shaft 36 is connected to driving system comprising gears,belts KB, etc., and is further connected to stepping motor KM.

Next, using the perspective view shown in FIG. 9, the structure ofperipheral parts of cap 41 will be described. Although the shape of cap41 will be described later in detail later, cap 41 is formed by plasticmaterial such as silicone rubber, etc. which has a high resistivityagainst mechanical creep as well as a high ratio of permeability forwater vapor, etc. A reference numeral 42 designates a cap keel made ofrigid material such as aluminum, stainless steel, etc., and as shown ina cross-sectional view in FIG. 10, short shafts 46a, 46b, 46c, 46d, and46e are fixedly mounted on cap keel 42 by means of screws. Short shafts46a-46e should desirably be made of a corrosion-inhibiting and rigidmaterial such as stainless steel, etc. In the present embodiment,although short shafts 46a-46e are fixed by screws, these can also becoupled by means of press fitting, bonding, or the like. Also, cap keel42 and shafts 46a-46e can be formed integrally by means of molding, etc.

Here, the formation of cap 41 is first made by coupling cap keel 42 andshort shafts 46a-46e as described above. Then, the coupled cap keel 42and short shafts 46a-46e are buried into an open forming die, and byputting silicone rubber, which is also the original material of cap 41,into the die or sandwiching silicone rubber between cap 41 and cap keel42, these are integrally formed by fusing into a one body. Here, theshape of the aforesaid forming die should match the external contour ofcap 41 as a matter of course. Now, a reference numeral 60 designates arecovery frame made of a corrosion-inhibiting rigid material such asstainless steel, and the four sides of recovery frame are bent up(60a-60d) in order to enhance rigidity. To recovery frame 60, shortshaft bearings 61a, 61b, 61c, 61d, and 61e are fixed by screws, etc.(not shown) to receive short shafts 46a-46e. In this respect, the methodfor coupling bearings 61a-61 e with frame 60 may also be either weldingor bonding. Also, as described later, short shaft 46a is fitted into anelongated hole while short shafts 46b-46d are fitted into the so-calledloose holes, and short shaft 46e is fitted to perform positioning. Inother words, each of the short shafts 46a-46e has a same outer diameter,and the inner diameter 61e₁ of short shaft bearing 61e and the outerdiameter of short shaft 46e are made to just fit each other. Short shaftbearings 61a-61e are made of polyacetal resin having excellentslidability against stainless steel short shaft 46e.

As shown in FIG. 9, an elongated hole 61a₁ is formed for short shaftbearing 61a against short shaft bearing 61e in the longitudinaldirection of cap 41. Then, the dimension of elongated hole 61a₁ in thetransverse direction is formed to fit short shaft 46a. The diameters ofholes 61b₁, 61c₁ and 61d₁ opened in short shaft bearings 61b, 61c, and61d are respectively formed larger than the outer diameters of shortshafts 46b-46d within a rage of 0.1 mm-1 mm. Then, at the outside ofshort shafts 46a-46e, compression springs 47a-47e are respectively heldby screws from the reverse side of recording frame 60 with short shaftstoppers 56a-56e sandwiched as shown in FIG. 9.

Compression springs 47a-47e are pressed between the cap keel and shortshaft bearings 61a-61e because the springs are held by screws. Themovement of cap 41 at this juncture will be described later.

Next, first wiper 50 and second wiper 52 are made of plastic materialsuch as rubber, etc. having a good abrasion resistance, and the straightportions of leading ends 50a and 52a of first and second wipers 50 and52 are strictly controlled to maintain the straightness as well as toprevent wear and dust, etc. Also, the aforesaid first wiper 50 andsecond wiper 52 are respectively fixed to first wiper stay 49 and secondwiper stay 51 by means of screws, etc. (not shown). First and secondwiper stays 49 and 51 are both made of corrosion-inhibiting rigid metalsuch as stainless steel, etc.

Further, as shown in FIG. 9, first wiper stay 49 and second wiper stay51 are held on recovery frame 60 by screws, and the projection 41a ofcap 41, which will be described later, and the wiper leading ends 50aand 52a are arranged to accurately parallel themselves at this juncture.Also the aforesaid projection 41a, wiper leading ends 50a and 52a, andthe mounting face of recovery frame 60 for wiper stays 49 and 51, andthe imaginary two-dot chain line α in FIG. 9 connecting the center linesof boss sections 59a₁ and 59b₁ of front cam gear 59a and rear cam gear59b are arranged to be in parallel accurately as described later. Also,as shown in FIG. 9, the structure is formed to enable the height of theleading end 52a of second wiper against recovery frame 60 to be higherthan that of the leading end 50a of first wiper against recovery frame60. In order to provide this structure, it is possible to change eitherthe heights of the aforesaid plastic portions made of rubber, etc. offirst and second wipers 50 and 52 or the height of rigid portions offirst and second wiper stays 49 and 51. Now, a reference numeral 54designates a recovery frame bearing, and recovery frame shaft 55 shownin FIG. 1A (control cross-sectional view) is allowed to fit theelongated hole 54a of recovery frame bearing 54 in the transversedirection. Here, in this respect, recovery shaft 55 is fixed to mainbody frame 63, but recovery frame shaft 55 may also be supportedrotatably by main body frame 63. Recovery frame shaft bearing 54 is madeof polyacetal resin having a good slidability and is fixedly screwed torecovery frame 60. Recovery frame bearing 54 is fixed against recoveryframe 60 in the direction indicated by arrow β in FIG. 9 at a positionwhich enables the center of the depth of elongated hole 54a to be in thecentral part of recovery frame 60. Also, here, the center of hole 61c₁of short shaft bearing 61c is positioned in the central part of recoveryframe 60 in the direction indicated by arrow β as shown in FIG. 9.Further, the center of hole 61b₁ of short shaft bearing 61b and that ofhole 61d₁ of short shaft bearing 61d are symmetrically positioned in thedirection indicated by arrow β with short shaft bearing hole 61c₁ as thecenter. Also, the center of elongated hole 61a₁ of short shaft bearing61a in the direction indicated by arrow β and the center of hole 61e₁ ofshort shaft bearing 61e are likewise positioned symmetrically in thedirection indicated by arrow β with the hole 61c₁ as the center. Now, itis desirable to equalize four distances between the centers of holes,i.e. the distance between the centers of holes 61a₁ and 61b₁, 61b₁ and61c₁, 61c₁ and 61d₁, and 61d₁ and 61e₁. Next, a reference numeral 62designates a recovery frame shaft which is arranged across both of theside plates of main body frame 63. This recovery frame shaft 62 isrotatably supported around a bearing (not shown) provided in main bodyframe 63. Further, to this recovery frame shaft 62, idler gears 57a and57b are fixedly mounted respectively at positions inside the main bodyframe 63 and outside the front cap guide 48a and rear cap guide 48bwhich will be described later. In view of assembling recovery frame 62in main body frame 63, parallel pins or spring pins (both not shown) andE ring stopper are used as means to fix idler gears 57a and 57b torecovery frame shaft 62. Further, to recovery frame shaft 62, outeridler gear 58 is fixed with D cut portion formed at an end of recoveryframe shaft 62 as its rotation stopper, with main body frame 63 beingsandwiched as shown in FIG. 9. Then, to idler gear 57a and 57b, camgears 59a and 59b are arranged to engage with each other. Cam gears 59aand 59b are rotatably supported on cam gear shafts 70a and 70b fixed tomain body frame 63 respectively at positions outside the cap guides 48aand 48b and inside the main body frame 63. Here, the modules and numberof teeth of gears 57a, 57b, 59a, and 59b are the same. Furthermore, gear58 and gears 57a, 57b, 59a, and 59b are of the same number of teeth.Then, gear 58 is connected to stepping motor CM.

As above described, the number of teeth thus arranged enables the gearsengaged with cam gears 59a and 59b to rotate one round exactly the sameas the cam gears completing one round, so that the rotational angles andpositions of these gears are detected by a microswitch slit type sensor(not shown), etc. to detect the position of the boss section 59a₁ of camgear 59a and the boss section 59b₁ of cam gear 59b. Therefore, if only agear, a timing pulley, or the like, which should complete one round insynchronism with the one rotation of cam gears 59a and 59b, is arrangedin the driving system for detecting the position of such gear, timingpulley, or the like, it is not necessary to make the number of teethidentical to each of the gears 57a, 57b, 59a and 59b as in the presentembodiment. To recovery frame 60, cap guides 48a and 48b are fixedlymounted in addition to these gears. Cap guides 48a and 48b are made ofpolyacetal resin having a good slidability. Then, grooves 48a₁ and 48b₁are formed on cap guides 48a and 48b to fit the boss sections 59a₁ and59b₁ of cam gears 59a and 59b in the transverse direction as shown inFIG. 10. Here boss section 59a₁ and boss section 59b₁ are arranged atpositions just opposite to each other.

Since the structure is of such as described above, recovery frame 60performs rocking motion in the direction indicated by arrow X in FIG. 10(central cross-sectional view) with recovery frame shaft 55 as thecenter when outer idler gear 58 is rotated.

Now, since the vicinity of recovery frame 60 is constructed with theparts described as above, recovery frame 60 is positioned by the planeformed by two-dot chain line α and recovery frame shaft 55 as shown inFIG. 9. Here, two-dot chain line α and head shaft 36 are arranged to beaccurately in parallel. Although recovery frame 60 is positioned by theplane formed by the aforesaid two-dot chain line α and recovery frameshaft 55, it is not fixed by the aforesaid structural members. Recoveryframe 60 is structured to be flexible in the directions indicated byarrow e and by curved arrow γ in FIG. 9.

Next, using FIG. 11, the arranging position of first recovery cap guide48a and second cap guide 48b is the direction indicated by arrow θ inFIG. 9 towards recovery frame 60 will be described in detail. On bothfirst and second cap guides 48a and 48b, U letter type holes 48a₁ and48b₁ are formed, and the space of U letter hole is precisely defined.The space of the aforesaid U letter holes 48a₁ and 48b₁ is indicated byarrow in FIG. 11. Then, first and second cap guides 48c and 48b arearranged on recovery frame 60 to allow the center of the shorter widthof projection 41a (indicated by arrow in FIG. 11) of cap 41 to be placedin the center of the aforesaid space of U letter holes 48a₁ and 48b₁.

Next, on first head arm 37a and second head arm 37b, circularprojections 37a₁ and 37b₁ are formed respectively on front head arm 37aand rear head arm 37b. Then, the arranging positions of the aforesaidcircular projection 37a₁ and 37b₁ are defined to allow the inkdischarging ports of nozzle section 38a to be placed in the centralposition of the circular projection. Also, the diameter of the aforesaidcircular projections 37a₁ and 37b₁ is formed to fit exactly the spacesof U letter holes on cap guides 48a and 48b.

Now, since the structure is arranged as described above, when recoveryframe 60 is raised by the rotation of cam gears 59a and 59b at the timeof capping, circular projections 37a₁ and 37b₁ of head arms 37a and 37bare respectively guided to U letter holes 48a₁ and 48b₁ of cap guides48a and 48b, and nozzle section 38a and projection 41a of cap 41 arejust oppositely placed.

Here, in the present embodiment, recovery frame 60 can be displaced inthe direction indicated by arrows θ and γ (in FIG. 9) by theconstruction as described earier. Therefore, according to the presentembodiment, even when there is a slight difference in the positions ofthe aforesaid U letter holes 48a₁ and 48b₁ and projection 37a₁ and 37b₁at the time of fitting, recovery frame can fit them reliably while beingguided by slant 48c and holes 48a₁ and 48b₁ to displace itself in thehorizontal direction if only projections 37a₁ and 37b₁ are in contactwith slant 48c of U letter holes 48a₁ and 48b₁.

Further, the positioning of cap 41 and front head plate 38c, which willbe described later, is performed naturally in this course of event.Also, even if recovery frame 60 approaches nozzle orifice face 38b withsome inclination, projection 41a and nozzle section 38a can approacheach other with the face to face positional relationship.

Next, using FIGS. 10 through 15, the shapes and movement of cap 41, capkeel 42, valve 43, valve cover 44, and waste ink tube will be described.

FIG. 10 illustrates the state immediately after head 38 and cap 41 arein contact with each other. FIG. 11 illustrates the state when head 38and cap 1 are parted. FIG. 12 illustrates the state when cap 41 is movedforwards head 38. FIG. 13 illustrates the state where projection 41acloses nozzle 38a by pressure, and spring 47 is resiliently deformed.FIG. 14 illustrates the state where cap 41 is parted from head 38, andFIG. 15 illustrates the standby state. In each of the figures, A is aside view observed from the location of side plate; B is across-sectional view in the transverse direction; and C is across-sectional view in the longitudinal direction. In FIG. 11, however,A is also a side view but B is a cross-sectional view in thelongitudinal direction.

At first, FIGS. 10A through 10C illustrate the state representing themoment cap 41 has come into contact with front head plate 38c. Cap 41has not been deformed as yet. In conjunction with FIG. 18B, thecross-sectional shape of cap 41 is described in detail. The sideportions of cap 41 are formed with inclination so as to widen thedistance between them as the cap is raised upwards as shown in FIG. 10B.The inclined side portions are connected to the curbed portionsindicated by mark a in FIG. 10B, and the thickness of the portions a aremade thinner than the other portions as illustrated in FIG. 10B.Although, in the present embodiment, the portions a are formed with asmooth curvature, these portions may also be formed in an abrupt edge.In the case of an abrupt edge in which these should be formed, thethickness of such edge portions could be made thinner. Likewise, in FIG.10C, the cross-sectional shape of cap 41 in the transverse direction isformed to open itself towards the outside as it is raised upwards as inFIG. 10C.

The cross-sectional shape of cap 41 in the transverse direction isformed in such a manner that the thickness of cap 41 contacting withfront head plate 38c is made thicker than that of the cross-sectionalshape of cap 41 in the longitudinal direction shown in FIG. 10B alsocontacting the aforesaid front head plate 38c. This is due to the factthat although the positioning of cap 41 against head 38 in thetransverse direction is accurately performed, the positioning in thelongitudinal direction is not performed accurately. Therefore, suchconstruction as is the present embodiment may not be needed if only thepositioning of cap 41 against head 38 is accurately performed in thelongitudinal direction. Now, reverting to FIG. 10C, the side portions ofcap 41 are connected to curbed portions b which change its shapesmoothly as in FIG. 10B, and the thickness of portions b is madethicker. In the present embodiment, the shape of cap 41 in FIGS. 10B and10C is such that the thickness thereof becomes increasingly thinnersmoothly towards as illustrated in these two figures. Now, reverting toFIG. 10B, in the closed space in cap 41, projection 41a integrallyformed with cap 41 is provided. The arranging position of projection 41ais defined so as to allow the top of R shaped portion 41c of projection41a to be located at a position against nozzle section 38a. The lengthof projection 41a in the longitudinal direction at both ends is madelonger than the entire length in which nozzle section 38a is arranged.Next, through hole 41b is provided on cap 41. The through hole 41b incap 41 is provided with through hole 41 provided on cap keel 42. Then,the aforesaid through hole 41b, valve 43 is fitted. The aforesaid valve43 being formed with plastic material, it can produce a state which isclosed from the atmosphere without any pressure exerted on valve 43.Here, the reason why valve 43 can properly function as a valve is thatwhile cap keel 42 is formed with rigid material as described earlier,the contact face between valve 43 and cap keel 42 is formed excellentprecision.

Next, around valve 43, valve cover 44 is mounted to enclose valve 43,and cap keel 42 and valve cover 44 are closedly fixed. Further, valvecover 44 is closedly coupled with waste ink tube 45. Cap 41 begins toapproach recording head 38 from the state shown in FIG. 10 by therotation of cam gears 59a and 59b in the direction indicated by arrow din FIG. 10A. Along the movement of the aforesaid cam gear 59a and 59b,the sides of cap 41 begin to move in the directions indicated by arrow cin FIG. 10B and FIG. 10C while maintaining contact with front head plate38c. This movement occurs because the sides of cap 41 are formed to openas the cap is raised upwards. Now, cap 41 is moved in the directionindicated by arrows c due to the shape of cap 41. In addition to this,it is due to the increasing pressure in the closed space in cap 41resulting from the reduction of volume of the closed space in cap 41. Asthe pressure in the closed space in cap 41 increases, valve 43 begins toopen, and air in the closed space begins to flow from valve 43 and wasteink (not shown) begins to flow towards waste ink tube 45. Further, FIG.12 illustrates the state where cam gears 59a and 59b have rotated in thedirection indicated by arrow d.

In FIG. 12B, the side of cap 41 is in contact with the rising portion ofthe edge of front head plate 38c and the movement in the directionindicated by arrow c in FIG. 10 is stopped. The side of cap 41 in thetransverse direction shown in FIG. 12C is formed thinner than thethickness of the side in the longitudinal direction as describedearlier. Therefore, its movement in the direction indicated by arrow cis stopped by the rigidity of the side itself. In the presentembodiment, the thickness of the side of cap 41 shown in FIG. 12C ischanged as described earlier, but if the thickness of the side of cap 41in the transverse direction is made thin as in the case of the thicknessof the side in the longitudinal direction as described above, the samefaction as the present embodiment can be materialized by allowing theside to be in contact with the rising portion of the edge of front plate38c.

Now, in FIG. 12B, the portions a of the sides of cap 41 are deformed asshown in FIG. 12B due to bending stress generated after the sides of thecap are in contact with the edges of front head plate 38c. The thickportions including the contacting faces of the sides of cap 41 receivebuckling load, and the aforesaid portions a, being deformed to bend, arenot buckled. This results in the similar deformation taking place in thesides of cap 41 including the portion b in FIG. 12C which is also beingdeformed. Here, in FIG. 12C, compression spring 47a has not been pressedas yet.

In FIG. 12B, the pressure in the aforesaid closed space generated by cap41 becomes higher than the pressure in the state represented in FIG. 10,and valve 43 is released to flow air in the closed space in cap 41 andthe aforesaid waste ink to waste ink tube 45.

In this respect, when cam gears 59a and 59b are further rotated in thedirection indicated by arrow d, cap 41 further approaches head 38 andthe projection 41a of cap 41 contacts nozzle 38a. Here, there is almostno deformation of cap 41 with the exception of projection 41a. Also,when cam gears 59a and 59b are still further rotated in the directionindicated by arrow d, compression spring 47a begins to deform, and thereaction generated by the aforesaid compression spring 47a causesprojection 41a of cap 41 to press nozzle section 38a. In this respect,only compression spring 47a is illustrated in FIG. 10 through FIG. 15,but the other compression springs 47b, 47c, 47d, and 47e function in thesame way as compression spring 47a. Here, the time needed for theaforesaid projection 41a to press nozzle 38a is approximately severalseconds which are required for liquid ink to circulate in head 38. Atthis juncture, a pump is actuated to circulate liquid ink.

In the above-mentioned embodiment the cap 41 and the projection 41a areintegrally formed of an elastic material such as rubber. However, thecap 41 may be a member separate from the projection 41a and the wholebody of the cap 41 does not have elasticity. At least the head dischargeport surface 38c and the contact section may be elastic and in this casea remaining upper part thereof may be of steel.

Now, FIG. 13 illustrates the state where compression spring 47a isdeformed as the above described, and boss sections 59a₁ and 59b₁ of camgears 59a and 59b are positioned at the top. In FIG. 13, there is almostno volume change in the closed space formed by the cap 41, and valve 43only shows the state to close air. Therefore, the pressure in the closedspace is equal to the atmospheric pressure. Hereinafter, the state ofeach part, when cam gears 59a and 59b are rotated from the state shownin FIG. 13 in the direction indicated by arrow e, will be described.Now, the rotational direction of cam gears 59a and 59b means therequired movement of boss sections 59a₁ and 59b₁ from the top to thebottom or from the bottom to the top as shown in FIG. 13, and even if,for example, cam gears 59a and 59b are rotated in the direction reverseto that indicated by arrow e in FIG. 13, the movements described belowshould take place in the same manner. In FIG. 14, the volume in theclosed space in cap 41 is again increased and the pressure in the closedspace becomes negative against the atmosphere, and valve 43 is closed asshown in FIG. 14. Therefore, in order to supplement the reduced volumein the closed space in cap 41, ink is discharged from nozzle section 38aof recording head 38. Ink remaining in nozzle section 38a is refleshed.

Finally, FIG. 15 illustrates the pheripheral parts including cap 41being in the standby state where an apparatus according to the presentinvention has not started performing operation such as recording,recovering, etc. In FIG. 15, the cam gears are at rest. In FIG. 15B, thepressure in the closed space in cap 41 is identical to the atmosphericpressure. At this juncture, there is no force exerted on valve 43 eitherto open or close to valve 43. However, due to the shape of valve 43,water vapor in the closed space in cap 41 is not released into theatmosphere.

FIG. 15D is a view showing another embodiment of guide member accordingto the present invention. On first cap guide 48a and second cap guide48b, V letter holes 48a₂ and 48b₂ are respectively formed, and thespaces in V letter holes are formed with excellent precision.

Next, on first head arm 37a and second head arm 37b, square projections37a₃ and 37b₃ are respectively formed, and the widths of the aforesaidprojections are formed to fit exactly the spaces of the aforesaid Vletter holes respectively.

Then, first head arm 37a₂ and second head arm 37b₂ are arranged to allowthe leading ends of square projections thereof 37a₃ and 37b₃ to materespectively with V letter holes 48a₂ and 48b₂ when the projection ofcap 41 is in contact with nozzle section 38a of head 38.

With a structure such as this, even if there is a slight difference inthe positions of the aforesaid V letter holes 48a₂ and 48b₂ and theaforesaid square projections 37a₃ and 37b₃, recovery frame 60 enablesthe holes 48a₂ and projection 37a₃ and the hole 48b₂ and projection 37b₃to be mated reliably because the frame can displace itself in thedirections indicated by θ and γ in FIG. 9.

FIG. 15E is a view showing still another embodiment of guide memberaccording to the present invention. On first head arm 37a₄ and secondhead arm 37b₄, U letter holes 37a₅ and 37b₅ are respectively formed, andthe spaces of U letter holes are formed with excellent precision.

Next, on first cap guide 48a and second cap guide 48b, circularprojections 48a₃ and 48b₃ are respectively formed, and the widths of theaforesaid circular projections are formed to fit exactly the spaces ofthe aforesaid U letter holes.

Then, first head arm 37a₄ and second head arm 37b₄ are arranged to allowthe leading ends of U letter holes 37a₅ and 37b₅ to fit circularprojections 48a₃ and 48b₃ respectively when the projection of cap 41 isin contact with nozzle section 38a of head 38.

With a structure such as this, even if there is a slight difference inthe positions of the aforesaid circular projections 48a₃ and 48b₃ andthe aforesaid U letter holes 37a₅ and 37b₅, recovery frame 60 enablesthe projection 48a₃ and hole 37a₅ and the projection 48b₃ and hole 37b₅to be mated reliably because the frame can displace itself in thedirections indicated by arrows θ and γ in FIG. 9.

Next, the ink supply and recovery systems will be described. This unitcomprises an ink tank, ink tubes, an ink pump, etc. to keep ink andsupply it regularly to a recording head and to remove bubbles generatedin the tubes, etc., as well as anything that may clog nozzles.

FIG. 16 is a view illustrating the concept of an embodiment according tothe present invention. In FIG. 16, an ink cartridge comprises recordinghead 38, ink pump 76, ink tank 86, waste ink absorber 96, and air duct87 which is called breather.

The initial ink supply to recording head 38 is carried out in a mannergiven below. In other words, ink pump 76 is actuated in a state wherecap 41 is closely contacted with the recording head (a state shown inFIG. 13 where projection 41a in cap 41 is in contact with nozzle section38a of recording head 38) to circulate ink from ink cartridge 86 in thedirection indicated by arrow E, so that the inside of the tubesincluding the inside of the recording head is filled with ink. At thistime, some ink is flown out to cap 41, but it is returned to inkcartridge 86 through waste ink tube 45 and collected to built-in inkabsorber 96.

When the initial ink supply is completed, recording head 38 is ready todischarge ink. The ink pump used in the present embodiment, however, isa pump which does not close the flow passage when the pump is at rest.Therefore, the ink supply at the time of discharging is carried out fromboth front and rear head ink couplers 38d and 38e.

When ink is reduced due to discharging, air should be drawn into thetank in an amount equal to the reduced amount of ink. Breather 87functions as an air duct for this purpose. In this breather 87, checkvalves capable of being opened by an extremely small difference inpressures are respectively arranged in both directions. Therefore, thevalves function if a slight pressure, either negative or positive, isgenerated in the tank, and operate as air holes substantially. However,the valves are also arranged to control dust intrusion and evaporation.

A reference numeral 92 designates a no-ink detector for detecting no-inkcondition in tank 94. The detection is carried out in a manner givenbelow. In other words, since float chamber 90 is open to the atmospherethrough breather 87 which is commonly provided for ink tank 94, theliquid level therein and float 89 which floats thereon indicate the samewater level 91a as liquid ink level 91 in ink tank 94. Therefore, at anappropriate location in the lower part of float chamber 90, sensor 88 isarranged for detecting a light interruption. Thus, when liquid level 91is lowered, i.e., float 89 is lowered following the lowering of waterlevel 91a in the area for detection, the emitting light from the sensor88 is interrupted, thereby detecting the no-ink condition.

Next, the recovery operation is described. The recovery operation is anaction to remove bubbles and cloggings which hinder the normaldischarging, and is performed in accordance with the recovery sequence,which will be described later, controlled by the recovery system. Therecovery operation, however, is exactly the same as the initial inksupply operation. In other words, ink pump 76 is actuated while cap 41is in contact with recording head 38 (the current state is illustratedin FIG. 13) to circulate ink in the direction indicated by arrow A, sothat bubbles are collected into the ink tank to release them to theoutside through the breather. Also, the contacting condition betweenprojection 41a in cap 41 and nozzle 38a is released to drive the pumpfor the removal of any clogging in the nozzle. At this time, pressurizedink is flown into float chamber 90. Then, float 89 is raised to closelycontact with upper face of float chamber 90 to cover the passage tobreather 87. Therefor, no ink is flown into breather 87.

FIG. 17 is a perspective view showing the construction of supply andrecovery systems, in which the structure of the present embodiment isactually employed. In FIG. 17, a reference numeral 73 designates thebase of this unit which also functions as a base for installing inkcartridge 86, which will be described later. Also, a reference numeral74 designates a member called a joint plate which is formed by fixingeach of various passage couplers. To this joint plate 74, there arecoupled cartridge guide 78 for positioning ink cartridge 86, cartridgejoints 79a, 79b, and 79c for connecting tubes to release air, waste inkjoint 81 for guiding waste ink produced at the time of recording towaste ink absorber 96 built in ink cartridge 86 through waste ink tank,air joint 80 for connecting the breather for releasing air with air tube83, first and second supply tube joints 84 and 85 for connecting firstand second ink supply tubes 71 and 72 with ink pump 76 which is drivenby pump motor 77. Thus, ink joint 79 connected to ink tank 94accommodated in ink cartridge 79a provides three functional sectionsintensively, first ink supply section 79a, second ink supply section79b, and air passage connecting section 79c, and with its structure,enables first ink supply inlet 95a, second ink supply inlet 75b and airinlet 95c to be coupled altogether, which are operationally related tothe function of ink tank 94.

For this purpose, the air passage section leading to the ink tank isformed by joints, thereby making it possible to construct the ink tankwith hard resin material to reserve a large quantity of ink withoutemploying ink bags.

Furthermore, by connecting first ink supply inlet 95a and second inksupply inlet 95b, and first ink supply section 79c and second ink supplysection 79b, an ink circulation passage is formed to perform ink supplyfrom both of the ink supply regions at the time of recording and tocirculate ink from the ink tank through the passage with the pumpinbetween, and to circulate ink from the recording head to the ink tankagain at the time of initial ink filling and recovery operation.

In other words, since the passage is formed by directly joining the tankand the supply passage, and further the air passage as describedearlier, it becomes possible to eliminate, in spite of the ink tankbeing made of hard plastic resin, such function as a sub-tank which hasconventionally been indespensable for a stable ink supply. In thepresent embodiment, these members are separately fixed to joint board74, but the structure may also be such that these members are.integrally formed with the joint board.

Further, to joint board 74, flow passage board 75 is coupled with flowpassage gloove 75a which functions as ink flow passage. In this portion,most of the ink flow passage pipings and connections are installed.

In other words, by fixedly arranging joint section 79 which is annexedto joint board 74 connected to ink tank 94, it becomes possible toprovide a structure thereby eliminating the operation related to inkpassage 75a in that particular portion.

As a result, a part of ink passage from ink tank 94 to the recordinghead can be formed only by coupling to the reverse side of joint board79 the flow passage plate 75 which constitutes a flow passage.

On the other hand, as described later, ink tank 94 built in inkcartridge 86 is flexibly accommodated in housings 93a and 93b whichconstitute the cartridge 86.

By accommodating the ink tank flexibly, it is possible to reliablyadjust with ease the coupling condition of the cartridge which should beinstalled against joint section 79 which is flexibly arranged, and inthis way, the installation of cartridge is carried out with assurance.

It is also possible to construct the ink passage from the ink tankwithout complicated piping arrangements simply by coupling joint board74 and flow passage plate 75 to form the required flow passage.

As shown in FIG. 18, there are accommodated in ink cartridge 86, thecommon housings 93a and 93b made of material having a good impactresistance, ink tank 94 made of resin having a good property againstfluid and waste ink absorber 96 made of a water absorptive materialhaving an excellent ink absorptive property such as felt or porousmaterial. The ink supply and air releasing are performed by connectingthese members with cartridge 79 on the side of joint plate 74 throughjoint section 95. Thus, the entire ink cartridge 86 is structured to bedetachably installed as a whole on base 73 provided on the side of theapparatus.

FIGS. 19A and 19B illustrate the structure of this part further indetail. FIG. 19A is a partially cutaway cross-sectional side viewshowing the principal parts of ink cartridge main body 86. FIG. 19B is apartially cutaway cross-sectional view showing joint section 95connected to the cartridge joint of the ink supply system. In order toprevent any ink leakage when ink cartridge 86 is removed, metal ball 99is provided in joint section 95 to press it against joint opening 95a bythe compression of spring 98. When the ink cartridge is detached fromthe unit, metal ball 99 is closely in contact with shealing rubber 101to close the opening 95a of the joint section.

Also, as shown in FIGS. 19A and 19B and FIG. 20 showing the frontcross-section of ink tank, ink tank has sloped surfaces or slants 94a,94b at its bottom. In other words, there are provided slant 94a forgathering ink flow into joint section 95 from behind, and slant 94b forgathering ink flow into joint section 95 from the side of ink tank 94.Ink is supplied to the ink supply system through guiding tube 100 whichis bent to be opened at the lowest bottom of the ink tank. A bottomsupport 93b supports the rear portion of the sloped surface 94a of theink tank 94. Thus, it is possible to collect all ink in the vicinity ofguiding tube 100 by forming slants 94a and 94b at the bottom of inktank, and to use ink without any waste. Also, it is possible to draw inkwithout a waste even if the apparatus is installed with a slightinclanation. With a structure such as this, the area is provided in thehousing to accommodate the aforesaid waste ink absorber 96 substantiallyin U shape.

Furthermore, in the present embodiment, it is necessary to couple threeflow passages, i.e., two ink supply passage and one air releasingpassage, in joint section 95, but in order to obtain reliable couplings,ink tank 94 is held in housings 93a and 93b as shown in FIG. 20 withspace 97 to allow the ink tank to move freely in an appropriate amount.

Especially, it is necessary to provide flexibility not only verticallyand horizontally but rotatably when a plurality of joints should beconnected. In the present embodiment, a slight rotatability ismaintained to obtain a rotatable flexibility against the central axis ofjoint section 95 by supporting ink tank 94 with spaces 97 (in thisembodiment, for example about 1.0 mm) and spaces 97a (for example, about1.0-2.0 mm) provided for both ends of ink tank 94 and by waste inkabsorber 96 which is soft like felt. A projection 93d supports a frontbottom of the ink tank 94. Hence it is possible to make connectionsreliably without any deviations in positioning. In this embodiment thejoints 95a, 95b and 95c of the ink tank are provided about 0.5 mm lowerwith respect to the body joints 79a, 79b and 79c so that the ink tank 94is connected to the body joints in a state which it floats about 0.5 mmto the body joints. Furthermore, in order to prevent any abnormal soundgenerated by the movement of ink tank 94 by vibrating impact, etc. orbreakage of housing as well as to effectively utilize space, the centralpart of waste ink absorber 96 is removed as shown in FIG. 18 to allowthe lowest bottom ink tank 94 to be fitted into the removed part, sothat the ink tank is held by the remaining portion of circumference.With this structure, impact can be absorbed by the softness of waste inkabsorber 96 and the required flexibility is maintained. In this way, theink tank is protected from the external impact and the clattering of inktank is also prevented because in this structure the waste ink absorberis fitted at the lowest bottom of the ink tank and at the same time, theink tank is held by soft material such as felt of the circumferentialportion of the waste ink absorber.

Next, the recovery sequence will be described. The recovery operation isneeded to maintain a normal recording. With this operation which isperformed by the linkage of recovery system and ink supply system,bubbles and cloggings in the flow passage are removed. FIG. 22 is aflowchart showing this operation. FIGS. 23A through 23D are schematicviews showing the system in operation. In FIGS. 23A through 23D, for thepurpose of simplifying description, a unit comprising recording head 38,head arms, etc. is defined as head unit 65, another unit comprising cap41, wipers 50 and 52, recovery frame 60, etc. is defined as cap unit 65.Head unit 65 is rotatable with head shaft 36 as its rotating centerwhile cap unit 64 is rotatable with recovery frame shaft 55 as itsrotating center. Hereinafter, the sequence of recovery operation will bedescribed.

In the normal standby state, the relationship between recording head 38and cap 41 is, as has been already described, that the closed state ismaintained as shown in FIG. 15 by slightly bending the periphery of thecap. The recovery operation begins as shown in FIG. 12 with pressingprojection 41a in cap 41 against nozzle 38a arranged on the top ofrecording head by rotating cam gears 59a and 59b (the cap unit positionat this juncture is referred to as press position) (S22-1). Next, inthis state, ink pump 76 is actuated to circulate ink in the supplypassage (S22-2) and remove bubbles in the tube. Projection 41a ispressed against nozzle 38a in order to prevent ink from being flown outfrom the nozzle because otherwise a part of ink is not circulated by thepressure generated by the ink pump and flown out of the nozzle asuseless waste ink.

Next, as indicated by arrow F in FIG. 23A, cap unit 64 descends (thisstate is referred to as retracted position) (S22-3), and further headunit 65 is rotated as indicated by arrow G in FIG. 23B while cap unit 64is rotated as indicated by arrow H in FIG. 23B to be in the wipingstarting position (S22-4). Subsequently, head unit 65 is rotated asindicated by arrow I in FIG. 23C to clean off ink droplets, dusts, etc.on discharging port face 38b of the recording head with wipers 50 and 52arranged in cap unit 64 (S22-5). Although FIG. 23C illustrates the stateas indicated by arrow I where discharging port face 38b of the recordinghead is passing a first wiper, there are two wipers provided in thepresent embodiment. Therefore, when the cleaning off by a second wiperis terminated, cap unit 64 again descends to the retracted position asindicated by arrow J in FIG. 23D, and head unit 65 returns to the homeposition (S22-7). Then, finally, cap unit 64 ascends to the normalstandby state as shown in FIG. 1 (S22-8) to complete the recoveryoperation.

The cleaning in the present embodiment will additionally be described.The recording head employed for the present embodiment has dischargingports formed across the entire recording width of recording medium,i.e., the so-called full line type as described earlier. However, in thecase where a discharging port face is extremely elongated as in thepresent embodiment, a sufficient cleaning cannot be performed with theuse of one blade just for a one-time wiping. This is due to thedifficulty in applying pressure by a blade equally all over thedischarging port face, which is now too long for such a cleaning.

In the present embodiment, therefore, two blades, blade 50 and 52, areemployed to clean off the discharging port face sequentially to obtainreliability in cleaning action.

Particularly, at the time of cleaning, it is important for the twoblades to contact with the discharging port face of recording head eachindividually to perform cleanings, so that the effect of double-wipingshould be obtained. With a sequential arrangement of two blades such asthis, the cleaning time can be shortened as compared with the case wherea cleaning action is taken twice with one blade. Also, in the presentembodiment, the size of blade 50 which contacts the recording head firstdiffers from the size of blade 52 which contacts it subsequently. Therecording head rotates with head shaft 36 as its rotating center, and inorder to place the leading end of the blade to be in contact with thedischarging port face within the path of the recording head to move, itis necessary to define the length of each blade accordingly. Therefore,it is also possible to perform the required cleaning by driving the capunit following the rotational movement of the recording head whilemaking the length of each blades 50 and 52 the same or making therelational length of each of them reversed.

Also, by making the length of each of plural blades contacting therotating head 38 different, it is possible to vary the length l of theleading end of the blade contacting the discharging port face 38c of thehead and/or the contacting degree θ₀ of each blade (FIG. 23E). Hence, itis possible to vary the force and area of each blade with which tocontact discharging port face 38c to control possible splashing ofadhered ink and dust on discharging port face 38c to the surroundingarea at the time of cleaning off.

Also, by making the contacting amount and/or contacting angle θ₀ of eachblade against discharging port face 38c greater sequentially followingthe order in which each of the blades are in contact with dischargingport face 38c of the head, it becomes possible to allow the first bladesto contact discharging port face 38c lightly when there are more ink ordusts adhered thereto, which should be cleaned off and the later bladesto contact it sufficiently to clean off the remaining ink and dusts.Consequently, while controlling the possible splashing of ink and dustsadhered to discharging port face 38c to the surrounding area, it ispossible to remove them completely.

Furthermore, when the first blade wipes discharging port face 38c, therest of blades function as protective wall (FIG. 23C) to prevent the inkand dusts removed by the first blade from being splashed to surroundingarea of the recovery system and eliminate the causes to stain therecording sheet or to electrically short circuit electronic circuitboards.

In this respect, it is not necessarily to limit the number of the bladesfor cleaning to two as described above, but more blades can also beemployed. Also, although in the present embodiment, the same material isused for both blades 50 and 52, a same material but of differentproperties or different materials may be used to improve the cleaningeffect.

Next, referring to FIG. 24, the sequence at the starting time ofrecording will be described.

The recording is started in a manner given below. At first, a signal tostart recording is received by the recording head at a step S24-1, therecording head at this juncture being in the standby state where onlythe cap covers the discharging port face of the recording head as shownin FIG. 15. Then, at a step S24-2, the cap unit is retracted to thestate in which the recording head and the cap are set apart as shown inFIG. 11, i.e., the retracted position.

Subsequently, at a step S24-3, while maintaining the state shown in FIG.11, a preparatory discharging of several ejections to several hundredejections is effectuated from the entire nozzles of the recording head.

Hence, the discharging condition of the entire nozzles of the recordinghead is equalized.

Then, after the preparatory discharging is terminated, the cap unit andhead unit are moved at a step S24-4 to constitute a starting conditionof wiping action as shown in FIG. 23A. Then at a step S24-5, a series ofwiping action is performed as shown in FIG. 23B through 23D, and at astep S24-6, the recording unit is moved further to the recordingposition as shown in FIG. 1 where such state is held. After that,recording signals are sequentially inputted to carry out recording asdesired.

Next, the recovery operation which is executed by circulating ink willbe described further in detail. In the present embodiment, as shown inFIG. 16, bubble sensor 103 (for example, a transmitting sensor, etc.) isprovided to enable detecting bubbles in ink supply tubes. Accordingly,it is possible to perform two different types of recovery operations,i.e., an automatic recovery to be carried out periodically each at apredetermined time, and an occasional recovery to be performed whenbubble sensor 103 detects any incidental bubble or bubbles. Theoccasional recovery becomes possible with the installation of bubblesensor 103, and with this, the incidental non-discharging hithertoexperienced can be reduced, thereby making it possible to improve thereliability of the apparatus. Particularly, in consideration of thesafety with which all bubbles are removed irrespective of the presenceof bubbles, the amount and location thereof, a considerably excessivecirculation time and number has been given to perform a sufficientremoval of bubbles. In the present embodiment, however, bubble sensors103a and 103b are provided at either sides of up and down streams of inkflow towards the recording head at the time of circulation. Therefore,if no bubbles are detected by both of the bubble sensors, the recoveryaction is immediately suspended. Particularly when bubble sensor 103barranged at the downstream of ink flow at the time of circulation shoulddetect a signal indicating that bubbles have been removed (no bubblepresence), the ink pump is stopped after a while (a period required forthe detected bubble exhausted to the tank from the current position ofthe sensor). Consequently, there is no need for providing any excessivecirculation time as has been required conventionally, resulting in thetermination of the recovery sequence in a shorter period of time. Also,there is an advantage that the reliability of bubble removal improvesbecause the recovery action is terminated after no bubble presence hasbeen detected. In this way, the amount of ink consumed for recoverybecomes small, which leads to the prevention of no ink condition at thetime of receiving facsimile or of no reception state during the recoveryoperation.

FIG. 25 is a block diagram showing the recording unit according to anembodiment of the present invention.

In FIG. 25, microcomputer (CPU) 101 controls the operation of the unitin accordance with the program stored in ROM 112 and data stored in RAM113.

Ink jet print head 102 performs recording by control (strobe) signalsfrom CPU after data each for a one-line portion has been received fromCPU.

Drivers 103, 104, and 105 for each of pulse motors, which will bedescribed later, supply appropriate currents to drive the motorsrespectively in accordance with step instructions from CPU.

Reference numerals 106,107 and 108 designate respectively a motor (Wmotor) for conveying recording sheet, a motor (K motor) for transportinghead, and a motor (C motor) for transporting cap unit.

Head position detecting sensor 109 and cap position detecting sensor 110detect the positions by means of on-off of microswitches, for example.

A reference numeral 111 designates a bubble sensor.

A motor (P motor) 115 for driving the ink pump is a DC motor whichrotates with on. A driver (transistor circuit) 114 supplies current toturn on the P motor by a signal from CPU.

Next, in accordance with a flowchart shown in FIG. 26, the operation atthe time of recording will be described.

At first, when the recording operation is started, W motor is driven fora required number of steps to convey recording sheet to a predeterminedposition (S26-2) .

Next, to head 38, a black data for a one-line portion is transmitted(S26-3).

Then, cap is retracted to the retracted position (S26-4). In thisrespect, C motor is driven for a predetermined number of steps, or iscontinuously driven until the moment sensor 110 detects that cap 41 hasmoved to the retracted position. Either methods are applicable(hereinafter the movement of head and cap are the same).

Next, the so-called empty discharging is performed by transmitting apredetermined number of strobe signals (S26-5) to head 38.

Then, while wiping action is being taken, head 38 is transported to therecording position. In other words, head 38 and wiper (cap unit 64) aretransported to the starting position for wiping (S26-6 and S26-7), andby advancing head 38 to the recording position as it is, wiping isterminated (S26-8).

Also, after that, cap 41 is returned to the retracted position (S26-9).

The recording operation is executed by repeating the transmission ofdata each for a one-line portion to head 38, the transmission of strobesignals, the recording of the one-line portion (S26-10 and S26-11), andthe driving of W motor to convey recording sheet for a one-line portion(S26-12) until the recording of a one-page portion is terminated.

Then, after the recording of the last line has been terminated (S26-13),head 38 is returned to the standby state (S26-14) and cap 41 is returnedto the capping position (S26-15 and S26-16).

After that, W motor is driven to exhaust recording sheet (S26-17) toterminate the recording operation.

Next, in accordance with FIG. 27, the recovery operation will bedescribed.

While the apparatus is in the standby state, CPU examines timer t₁ inthe CPU as well as the bubble sensor. If timer t₁ indicates apredetermined time T₁ (24 hours, for example), the recovery operation isstarted (S27-2).

Also, even when the timing is not t₁ =T₁, the recovery operation isstarted if bubble sensor 111 is on (the presence of bubble indicated)(S27-3).

The recovery operation is performed as follows:

At first, C motor is driven to transport cap 41 to the pressing position(S27-5).

Next, P motor on signal is output to rotate P motor (S27-6).

Then, the output of bubble sensor 111 is detected, and when the sensoroutput is turned off, counter t₂ in the CPU starts counting (S27-7 andS28-8). When counter t₂ indicates a predetermined value T₂ (S27-9), timet₂ is cleared (S27-10), and turn off P motor (S27-11).

Then, the wiping action is actuated.

At first, cap is transported to the retracted position (S27-12).Subsequently, after transporting head 38 to the starting position forwiping, cap 41 is transported to the wiping position (S27-13 andS27-14), and then wiping is performed (S27-15) by transporting head 38to the position for terminating wiping (printing position). Cap 41 isagain returned to the retracted position (S27-16) and to the cappingposition after head 38 has been returned to the standby position(S27-17). Then, the apparatus is again in the standby state.

This terminates the recovery operation.

The present invention provides means for generating heat energy (forexample, an electrothermal converter, a laser light, etc.) for theutilization of energy for ink discharging especially for ink jetrecording method, and in a recording head and recording apparatus usinga method to activate changes in a state of ink by utilizing theaforesaid heat energy, the present invention is particularly effective.

For the typical structure and principle of an invention of the kind, itis preferable to employ the fundamental principle disclosed in thespecifications of, for example, U.S. Pat. Nos. 4,723,129 and 4,740,796.This method disclosed in applicable to the so-called on-demand type aswell as to the continuous type. Particularly in the case of theon-demand type, by applying at least one driving signal, correspondingto recording information and providing a rapid temperature rise whichexceeds nucleate boiling, to an electrothermal converter arranged forsheet or liquid passage holding liquid (ink), heat energy is generatedin the electrothermal converter, and film boiling is accordinglygenerated on the thermal active face of recording head. As a result,bubbles are formed in the liquid (ink) one to one by this driving signaleffectively. By the growth and contraction of this bubble, the liquid(ink) is discharged through the discharging port to form at least onedroplet. If this driving signal is made to be a pulse type, the growthand contraction of bubble can be effectuated instantaneously andappropriately, and it should be more preferable to employ such systembecause with it, a discharging of liquid. (ink) having an excellentresponsibility can be attained. For a driving signal of the pulse type,those disclosed in the specifications of, for example, U.S. Pat. Nos.4,463,359 and 4,345,262 should be suitable. In this respect, ifconditions disclosed in the specification of U.S. Pat. No. 4,313,124concerning an invention of the ratio of temperature rise on theaforesaid thermal active face are employed, a further excellentrecording can be performed.

For the structure of recording head, those structures, in which athermal active unit is arranged in a bending region, disclosed in thespecifications of U.S. Pat. Nos. 4,558,333 and 4,459,600 are included inthe present invention in addition to a combination structure (linearliquid flow passage or right angled liquid flow passage) of dischargingports, liquid passage, and electrothermal converter such as disclosed ineach of the above mentioned specifications. Besides, the presentinvention is still effective for the structures based on the structuredisclosed in Japanese Laid-Open Patent Application No. 59-123670 inwhich common slits against a plurality of electrothermal convertersfunction as discharging ports of the electrothermal converter, and thestructure disclosed in Japanese Laid-Open Patent Application No.59-138461 in which an opening for absorbing the pressure wave of heatenergy is used for the discharging port.

Particularly, the present invention is effectively applicable to therecording head of a full line type with a length to cover the width of amaximum recording medium which can be recorded by the recording head.For a recording head such as this, a structure in which a plurality ofrecording heads as disclosed in the above-mentioned specifications arecombined to meet the requirements of such length or a structure in whichone recording head, integrally formed, is adopted may be applicable, butthe present invention displays the above-mentioned effects moreefficiently.

In addition, the present invention is effectively applicable to theinstallation in the main body of an apparatus either in the case of arecording head of chip type which is freely replaceable to enable theelectrical connection with the main body of the apparatus or the inksupply from the main body of the apparatus or in the case of a cartridgetype recording head which is integrally mounted in the recording headitself.

It is also desirable to add the recovery means for the recording head,preparative auxiliary means, etc. which constitute a recording apparatusaccording to the present invention because such addition makes theeffects of the present invention more stable. These means arespecifically capping means for recording head, wiping means, pressuringor absorbing means, electrothermal converter, or another heating elementor preparative heating means by the combination of these elements, andaside from discharging for regular recording, it is also effective toeffectuate a preparatory discharging mode for performing a stablerecording. Furthermore, the present invention is extremely effective fora recording apparatus having at least one mode for recoloring withdifferent colors or for full color with mixture of colors by the use ofrecording heads which are integrally structured into one head or by thecombination of plural heads, not to mention the recording mode ofprincipal color such as black, etc. as recording mode for a recordingapparatus.

In the embodiment set forth above according to the present invention,the description has been made of the case where liquid ink is used, butthe present invention is also applicable to solid ink at roomtemperature as well as to ink becoming soft at room temperature. In theabove-mentioned ink jet apparatus, it is usual to perform temperaturecontrol to make viscosity of ink to be in the range of stabledischarging by adjusting the temperature of ink itself more to be than30° C. but less than 70° C. Therefore, if only ink becomes fluid at thetime of applying recording signals in use, those kinds of ink are alsousable. Furthermore, the present invention is applicable to the use ofink having the property that the ink becomes fluid only by heat energysuch as the one which can be discharged as liquid ink when it becomesfluid by the application of heat energy in response to recording signalsor ink already becoming solidified at the time of reaching recordingmedium by utilizing positively the temperature rise caused by heatenergy as energy to change the state of ink from solid to fluid forprevention or by using ink which is solidified when it is left for thepurpose of preventing evaporation. In such case, ink can be held asliquid or solid state in a concave of porous sheet or through holes asdescribed in Japanese Laid-Open Patent Application No. 54-56847 orJapanese Laid-Open Patent Application No. 60-71260, and is placedagainst the electrothermal converter in such mode. In the presentinvention, the performance of the above-mentioned film boiling method ismost effective when each of the above-mentioned kinds of ink isemployed.

Furthermore, the mode of an ink jet recording apparatus according to thepresent invention is such that in addition to facsimile apparatus havingreceiving and transmitting functions as in the present embodiment, itcan be used as image output terminal for information processingapparatus such as computer, etc, copying apparatus combined with reader,etc. or the like.

In the present embodiment, a recording head is used for the recoveryoperation by circulation with ink supply tubes arranged at both endsrespectively, but the present invention is also applicable to arecording head of such type that it has only one ink supply tube andperforms recovery operation by suction from the front face of nozzle asa matter of course. It is also possible to reduce manufacturing cost byforming bubble sensor integrally with the constituents of the head.

As set forth above, according to the present invention, it is possibleto perform an accurate mating of ink jet recording head and cappingmeans without the precision of each individual part and preciseadjustment at the time of assembly.

Furthermore, according to the present invention, it is possible toremove ink adhered to orifice face by a plurality of cleaning members,so that ink can be removed completely. It is further possible accordingto the present invention to remove effectively ink strongly adhered tothe orifice face by the plural cleaning members each having differentcontacting area, contacting angle, and contacting position provided bydifferent sizes of the cleaning members.

We claim:
 1. An ink discharge recovery mechanism comprising:supportmeans for rotatably supporting a full-line ink jet recording head forrotation about an axis parallel to a longitudinal direction of an inkdischarge port surface of said recording head, said discharge portsurface having a plurality of discharge ports for discharging an ink torecord across the width of a recording region of a recording medium,wherein said ink discharge port surface moves along a predetermined arcas said recording head is rotated; and a plurality of wiping members,each having a width sufficient for wiping said discharge port surface,wherein each said wiping member has a different length so thatsuccessively longer wiping members wipe said discharge port surface assaid discharge port surface moves along the predetermined arc, andwherein a contact force with which said wiping members wipe saiddischarge port surface varies within said discharge port surface.
 2. Anink discharge recovery mechanism according to claim 1, furthercomprisingcapping means for covering said discharge ports of said inkdischarge port surface.
 3. An ink jet recording apparatuscomprising:support means for rotatably supporting a full-line ink jetrecording head for rotation about an axis parallel to a longitudinaldirection of an ink discharge port surface of said recording head, saiddischarge port surface having a plurality of discharge ports fordischarging an ink to record across the width of a recording region of arecording medium, wherein said ink discharge port surface moves along apredetermined arc as said recording head is rotated; capping means forcovering said ink discharge ports of said ink jet recording head; and aplurality of wiping members, each having a width sufficient for wipingsaid discharge port surface, wherein each said wiping member has adifferent length so that successively longer wiping members wipe saiddischarge port surface as said discharge port surface moves along thepredetermined arc, and wherein a contact force with which said wipingmembers wipe said discharge port surface varies within said dischargeport surface.
 4. A method for recovering an ink jet recording apparatus,said method comprising the steps of:rotating a full-line ink jetrecording head about an axis parallel to a longitudinal direction of anink discharge port surface of said recording head, said discharge portsurface having a plurality of discharge ports for discharging ink torecord across the width of a recording region of a recording medium,wherein said ink discharge port surface moves along a predetermined arcas said recording head rotates; contacting said discharge port surfacewith a plurality of wiping members, each having a width sufficient forwiping said discharge port surface, wherein each said wiping member hasa different length so that successively longer wiping members wipe saiddischarge port surface as said discharge port surface moves along thepredetermined arc, and wherein a contact force with which said wipingmembers wipe said discharge port surface varies within said dischargeport surface.
 5. An ink discharge recovery mechanism according to claim1, wherein said short wiping member and at least one longer said wipingmember are made of a same material.
 6. An ink jet recording apparatusaccording to claim 3, wherein said short wiping member and at least onelonger said wiping member are made of a same material.
 7. A recoverymethod according to claim 4, wherein said short wiping member and atleast one longer said wiping member are made of a same material.
 8. Anink discharge recovery mechanism according to claim 1, wherein saidshort wiping member and at least one longer said wiping member havedifferent contacting amounts and/or contacting angles against saiddischarge port surface.
 9. An ink discharge recovery mechanism accordingto claim 2, wherein said short wiping member and at least one longersaid wiping member have different contacting amounts and/or contactingangles against said discharge port surface.
 10. An ink jet recordingapparatus according to claim 3, wherein said short wiping member and atleast one longer said wiping member have different contacting amountsand/or contacting angles against said discharge port surface.
 11. Arecovery method according to claim 4, wherein said short wiping memberand at least one longer said wiping member have different contactingamounts and/or contacting angles against said discharge port surface.12. An ink discharge recovery mechanism according to claim 1, whereinsaid short wiping member and at least one longer said wiping member aremade of different materials.
 13. An ink jet recording apparatusaccording to claim 3, wherein said short wiping member and at least onelonger said wiping member are made of different materials.
 14. Arecovery method according to claim 4, wherein said short wiping memberand at least one longer said wiping member are made of differentmaterials.
 15. An ink discharge recovery mechanism according to claim 1,wherein said ink jet recording head discharges ink by utilizing heatenergy, and is provided with an electrothermal converter which generatessaid heat energy.
 16. An ink let recording apparatus according to claim3, wherein said ink jet recording head discharges ink by utilizing heatenergy, and is provided with an electrothermal converter which generatessaid heat energy.
 17. A recovery method according to claim 4, whereinsaid ink jet recording head discharges ink by utilizing heat energy, andis provided with an electrothermal converter which generates said heatenergy.
 18. An ink discharge recovery mechanism according to claim 1wherein said recovery mechanism is used in a facsimile apparatus havinga receiving mechanism for receiving externally-provided imageinformation through a communication line.
 19. An ink jet recordingapparatus according to claim 3 wherein said recording apparatus is usedin a facsimile apparatus having a receiving mechanism for receivingexternally-provided image information through a communication line. 20.A recovery method according to claim 4 wherein said method is used in afacsimile apparatus having a receiving mechanism for receivingexternally-provided image information through a communication line. 21.An ink discharge recovery mechanism according to claim 1 wherein saidink jet recording head contains ink to be used for recording.
 22. An inkjet recording apparatus according to claim 3 wherein said ink jetrecording head contains ink to be used for recording.
 23. A recoverymethod according to claim 4 wherein said ink jet recording head containsink to be used for recording.
 24. An ink discharge recovery mechanismcomprising:support means for rotatably supporting a full-line ink jetrecording head for rotation about an axis parallel to a longitudinaldirection of an ink discharge port surface of said recording head, saiddischarge port surface having a plurality of discharge ports fordischarging an ink to record across the width of a recording region of arecording medium, wherein said ink discharge port surface moves along apredetermined arc as said recording head is rotated; and a wiping memberhaving a width sufficient for wiping said discharge port surface,wherein a contact force with which said wiping member wipes saiddischarge port surface varies within said discharge port surface as saiddischarge port surface moves along the predetermined arc.
 25. An ink jetrecording apparatus comprising:support means for rotatably supporting afull-line ink jet recording head for rotation about an axis parallel toa longitudinal direction of an ink discharge port surface of saidrecording head, said discharge port surface having a plurality ofdischarge ports for discharging an ink to record across the width of arecording region of a recording medium, wherein said ink discharge portsurface moves along a predetermined arc as said recording head isrotated; capping means for covering said ink discharge pores of said inkjet recording head; and a wiping member having a width sufficient forwiping said discharge port surface, wherein a contact force with whichsaid wiping member wipes said discharge port surface varies within saiddischarge port surface as said discharge port surface moves along thepredetermined arc.
 26. A method for recovering an ink jet recordingapparatus, said method comprising the steps of:rotating a full-line inkjet recording head about an axis parallel to a longitudinal direction ofan ink discharge port surface of said recording head, said dischargeport surface having a plurality of discharge ports for discharging inkto record across the width of a recording region of a recording medium,wherein said ink discharge surface moves along a predetermined arc assaid recording head rotates; contacting said discharge port surface witha wiping member having a width sufficient for wiping said discharge portsurface, wherein a contact force with which said wiping member wipessaid discharge port surface varies within said discharge port surface assaid discharge port surface moves along the predetermined arc.